Hemiarthroplasty with glenoid reaming improved severely arthritic shoulder function at 2 years

Patients showed significant improvements in 10 of the 12 individual functions included in the Simple Shoulder Test.

Performing a humeral hemiarthroplasty combined with concentric glenoid reaming can significantly improve self-assessed shoulder comfort and function in patients with severe glenohumeral arthritis, according to a study by researchers in Seattle.

The procedure also eliminates the risk of glenoid component failure associated with total shoulder arthroplasty, the study authors noted.

Joseph R. Lynch, MD, and colleagues at the University of Washington, evaluated outcomes for 35 shoulders of 34 patients treated with the procedure at an average age of 57 years. The study included 31 men and three women followed for at least 2 years.

The surgical technique involves performing an uncemented humeral hemiarthroplasty combined with glenoid reaming to a diameter 2 mm larger than the humeral head of the prosthesis, according to the study, published in the American edition of the Journal of Bone and Joint Surgery.

"Reaming is conservative, preserving as much bone stock as possible. It is continued only until a concentric spherical surface is achieved across the entire face of the glenoid," the study authors wrote.

Investigators used the Simple Shoulder Test (SST) to evaluate self-assessed improvement in shoulder function.

At 2.7 years mean follow-up, patients had gained an average of 4.7 functions, from an average of 4.7 functions preoperatively to 9.4 out of a possible 12 functions (P<.00001), according to the study.

Significant improvements were noted in 10 of the 12 individual functions included in the SST, ranging from P<.022 to P<.00001, the authors noted.

Preoperatively, 256 of 420 total possible shoulder functions - or 12 functions for each of the 35 shoulders - were absent. Of these, 181 functions were regained postoperatively, yielding a 71% overall likelihood of regaining a lost function, according to the study.

"Similarly, of the 164 shoulder functions that were present preoperatively, 17 were lost after surgery, making the overall likelihood of losing a function 10%," the authors wrote. Two shoulders experienced a decrease in the number of shoulder functions able to be performed and one shoulder had no change, they noted.

Forward elevation significantly improved on average from 60° preoperatively to 138° at final follow-up. External rotation also significantly improved, from 14° preoperatively to 42°, according to the study.

"With the numbers studied, the final shoulder function and the change in shoulder function were not significantly affected by age, gender, diagnosis and the presence or absence of medial glenoid erosion, eccentric glenoid wear or glenohumeral joint space on preoperative radiographs," the authors wrote.

"Lastly, shoulder function at the time of the final follow-up was not different for shoulders that had previous surgery in comparison with those that had no previous surgery," they wrote.

However, patients who showed a regenerated joint space had a significantly greater self-assessed final functional outcome. Also, patients who had a concentric vs. an eccentric glenoid preoperatively showed a greater improvement in self-assessed shoulder function, they noted.

For more information:
Lynch JR, Franta AK, Montgomery WH, et al. Self-assessed outcome at two to four years after shoulder hemiarthroplasty with concentric glenoid reaming. J Bone Joint Surg Am. 2007;89-A:1284-1292.